Robbie Diack is a man on a mission. A guy with something to prove to himself, his team mates, the Ulster supporters and the rugby world in general.

For although he started in 10 of Ulster’s 22 RaboDirect PRO12 games last season and made 11 appearances from the bench — eight in the PRO12 and three the Heineken Cup — 2011-12 was a huge disappointment for the big South African.

As a result the now-Irish-qualified 26-year-old back row forward feels he has a point to make this time.

He gets a chance to start doing that on Friday night when Ulster take on Glasgow Warriors at Ravenhill in the opening PRO12 game of the new campaign (7.05pm).

There is evident frustration in his voice when he says: “I had a bit of a knee injury at the end of last season so unfortunately I wasn’t involved in the Heineken Cup final.”

Then, tellingly, he adds: “But I wasn’t going to be involved in that anyway.”

There is a lengthy pause as he attempts to come up with a diplomatic means of describing his feelings on how last season panned out.

Finally, after several false starts, he offers: “I just wasn’t really involved as much as I’d like to have been last year. It wasn’t really a case of injuries or anything like that; I played a lot of games from the bench so I never really got much momentum or confidence is my rugby.

“I think that’s why I’ve really enjoyed it so far this season. I’ve had three 80-minute games on the bounce so I have been building my confidence up and enjoying playing again.

“I’ve had a point to prove in pre-season and in the three games so far.”

But he hastens to differentiate between training and friendly matches rather than competitive fixtures with points at stake.

“It’s easy to have a good pre-season, but it’s difficult to put that into the games on a Friday night,” he stresses.

“You can be strong in the gym and you can be fit in the field, but if you don’t perform on Friday nights it means nothing.

“That has been my main aim — to bring that motivation and attitude into the game on Friday night. I’ve enjoyed the amount of game time I have been given so far and I think my confidence has increased as a result.

“I think I’ve wanted to prove my capabilities to a few people. I want to prove to my team-mates what I’m capable of. I needed to remind myself of that, too, so pre-season has really been good for me.

“I’ve got a lot of positive feedback so I’m really looking forward to playing on Friday night. We train and work so we can be involved in these big games so it will be exciting.

“Pre-season has been tough enough and it has been long, but we know this is what it has been for,” he says.

Equally effective and comfortable at six or eight, Diack — 6ft 6ins and just under 18 stone — doesn’t mind where he plays. Inclusion is all that counts.

“They’re both really similar positions,” he explains.

“At eight you have a bit more responsibility with the ball at the back of the scrum, while at six you’re a little bit freer, but they’re both really the same, so either is fine for me. Just to be involved in the team is what matters. That is a fantastic honour so I’ll be happy to take either jersey.”

He knows that when Stephen Ferris, Chris Henry and Roger Wilson are available for selection, competition for places in the Ulster back row is going to be intense.

“It’s going to be a tough fight, but I suppose that’s what makes our squad environment so healthy. There’s good depth, certainly in our loose forwards, and that makes everyone determined to perform to the best of their potential,” he said.

“With so many players wanting to play you’ve really got to be at the top of your game week in and week out.

“Right now my target is just to make sure that I can get into the team and play a bit more rugby than last year,” he confirms.

“That is completely in my hands,” he adds, underlining his acceptance of the fact that inclusion or omission reflect how the coaching staff assess what a player has — or has not — shown in training.

And what he has shown to date has persuaded Mark Anscombe that Diack deserves a place.